A wireless local area network (wireless local area network, WLAN) can provide a wireless data transmission service in a limited range for a terminal on the wireless local area network. In a WLAN (also referred to as Wi-Fi, Wireless Fidelity, Wireless Fidelity) based on IEEE 802.11, a terminal device therein can also be connected to the Internet (Internet) by using a device such as a gateway. Because of advantages such as rapid deployment, convenient use, and high transmission rate, Wi-Fi has been widely used in various industries.
It is stipulated in the IEEE 802.11 standard that in a WLAN, addressing is performed based on a Media Access Control (Media Access Control, MAC) address. Generally, an eavesdropper may obtain MAC addresses of transmitting and receiving parties of a wireless message by receiving and analyzing the message on an air interface. By means of tracing a MAC address of a terminal, privacy information of a user of the terminal, such as a place or a time at which the user frequently appears, may be obtained, and by means of analyzing a large amount of data, privacy information of the user of the terminal, such as living habits, interests and hobbies, and even social relations, may be learned.
To ensure security of user privacy, currently, there is a solution for allocating an addressing identifier to a station; however, this is not enough to completely resolve a problem of tracing user privacy by using a MAC address. For example, within a period of time, an access point (Access Point, AP) allocates a temporary MAC address to a terminal in a basic service set served by the access point. If an eavesdropper acquires MAC addresses of all terminals in the basic service set, when the eavesdropper finds that a MAC address no longer appears while another MAC address that is new appears, the eavesdropper can determine that the new MAC address is a modified MAC address of the original terminal, and therefore, continues to trace the terminal.